Consider these chemical equations. n2(g) + 3h2(g) → 2nh3(g) c(s) + 2h2(g) → ch4(g) 4h2(g) + 2c(s) + n2(g) → 2hcn(g) + 3h2(g) which equation(s) do you need to reverse in order to calculate the overall equation for the formation of hcn and h2 from nh3 and ch4? check all that apply. n2(g) + 3h2(g) mr003-1.jpg 2nh3(g) c(s) + 2h2(g) mr003-2.jpg ch4(g) 4h2(g) + 2c(s) + n2(g) mr003-3.jpg 2hcn(g) + 3h2(g) what must you do before adding the equations?